Iridium(III)-Catalyzed Tandem Annulation of Pyridine-Substituted Anilines and α-Cl Ketones for Obtaining 2-Arylindoles

Rhodium(III)-catalyzed C-H alkylation of arylhydrophthalazinediones with α-Cl ketones as sp3-carbon alkylated agents

A Rh(III)-catalyzed C-H bond direct alkylation between 2-arylphthalazine-1,4-diones and α-Cl ketones, which are sp³-carbon synthons, under mild conditions has been disclosed. The corresponding phthalazine derivatives are readily obtained in moderate to excellent yields with a wide range of substrates and high functional group tolerance. The practicality and utility of this method are demonstrated by the derivatization of the product.

Rhodium(III)-Catalyzed Sequential Cyclization of N-Boc Hydrazones with Propargylic Monofluoroalkynes via C-H Activation/C-F Cleavage for the Synthesis of Spiro[cyclobutane-1,9'-indeno[1,2-a]indenes]

An effective rhodium(III) catalysis for the construction of valuable tetracyclic compounds is described herein. This domino process involving the C-H activation/[3 + 2] annulation/intramolecular Friedel-Crafts reaction sequences of simple and readily available N-Boc hydrazones and propargylic monofluoroalkynes afforded fused tetracyclic spiro[cyclobutane-1,9'-indeno[1,2-a]indenes] in moderate to good yields, featuring three C-C bond formation. Moreover, control experiments indicated that the C-H activation might be involved in the rate-determining step.

Pd-catalysed intramolecular transformations of indolylbenzenesulfonamides: ortho-sulfonamido-bi(hetero)aryls via C2-arylation and polycyclic sultams via C3 arylation

Indolyl substituted iodo-sulfonamides deliver 2-aryl(sulfonamido)indoles in the presence of Pd(OAc)2/Ph3P/Et3N; the same reactants, using Pd(OAc)2/Ph3P/K2CO3, afford indole-fused sultams.

Copper(II)-catalysed direct C3-H esterification of indoles assisted by an N,N-bidentate auxiliary moiety

The regioselective direct C3-esterification of indoles with OXA is developed in an efficient reaction with carboxylic acids using the catalyst CuBr2 and oxidants Ag2CO3 and K2S2O8. The simple experimental procedure is proved to be broadly applicable to a range of substrates, including aromatic and aliphatic acids, and the corresponding products were obtained in good yields up to 87%. At the same time, it provides a valuable approach to produce C3-benzyl derivatives of indoles through reaction with benzyl carboxylic acid under the same reaction conditions.